However, young BALB/c mice were significantly faster in the recruitment of GATA-3+ T cells to the site of infection compared to age-matched C57BL/6 mice, which was linked with the more robust expression of the small intestinal homing receptor CCR9 binding the chemokine CCL25 which is selectively expressed in the small intestine19,20. The gene discussed is CCR9; the disease is infection.